Feng Wu

In cold clouds of interstellar gas, carbon hides inside carbon monoxide (CO) molecules, like sugar dissolved in tea. But near hot, massive stars, this 'tea' boils: harsh radiation tears the molecules apart, and carbon escapes as lone atoms or ions.

Three floats on water bob chaotically. But three helium atoms cooled to near absolute zero behave differently, as if obeying an invisible law of similarity. Their mutual attraction is so weak that the atoms form a loose cloud.